JP7422794B2 - Machine tool table equipment - Google Patents

Description

The present invention relates to a table device for a machine tool having a rotary table that can rotate at high speed.

Patent Document 1 discloses that a table plate body and a table main shaft are rotatably supported by a device main body via bearings, and a shaft is cooled in a shaft gap between the table main shaft and a shaft portion passing through a center hole of the table main shaft. A motor-directly driven rotary table device is described in which the interior of the rotary table device can be cooled by circulating liquid.

JP2019-176551A

In the rotary table device of Patent Document 1, the cooling liquid is passed between the rotating table main shaft and the stationary shaft portion, so the structure for preventing leakage of the cooling liquid from around the table main shaft becomes complicated. Furthermore, in the rotary table device of Patent Document 1, the motor that rotationally drives the table main shaft is located away from a portion through which the cooling fluid flows, so that the cooling effect of the motor is insufficient.

In the rotary table device of Patent Document 1, since the motor is insufficiently cooled, the bearing that rotatably supports the table main shaft and is provided adjacent to the motor cannot be cooled.

The technical problem of the present invention is to solve these problems of the conventional technology, and it is possible to effectively cool the rotor of the drive motor that rotates the rotary table, thereby making it possible to rotate the rotary table at high speed. The purpose is to provide table equipment.

In order to achieve the above-mentioned object, according to the present invention, a table device for fixing a workpiece of a machine tool includes: a table base; a rotary table rotatably attached to the table base about a predetermined rotation axis; A drive motor having a rotor coupled to a rotary table and a stator coupled to a table base so as to face the rotor, the drive motor rotationally driving the rotary table, and a side surface of the rotor opposite to the stator. It has a cylindrical member coupled to a side surface, and a plurality of fin members formed on the inner circumferential surface of the cylindrical member, the plurality of fin members being arranged in the direction of the rotation axis and facing toward the front. It has a plate-shaped outer fin extending in a direction perpendicular to the rotation axis, and a plurality of plate-shaped fin members arranged between the fin members of the outer fin, and is fixed to a table base. A table device is provided that includes inner fins and a fin refrigerant passage through which a refrigerant for cooling the inner fins flows.

According to the present invention, while the drive motor rotationally drives the rotary table, the heat generated from the drive motor, particularly the rotor, is transported to the outer fins by thermal conduction, and the heat generated by the drive motor is transferred to the outer fins by heat conduction, and the air between the respective fin members of the outer fins and the inner fins is can be further transported from the outer fins to the inner fins by convective heat transfer, and from the inner fins to the entire table base by heat conduction. In this way, according to the present invention, it is possible to effectively cool the rotor of the drive motor that rotationally drives the rotary table, which has conventionally been difficult to cool.

Since the rotor of the drive motor is usually thermally coupled through the rotary table to a bearing that rotatably supports the rotary table on the table base, the present invention allows the rotary table to be operated at high speed by cooling the rotor. This also prevents the bearings from overheating when the rotary table is rotated at high speeds, making it possible to rotate the rotary table at high speed.

FIG. 2 is a cross-sectional view of a table device according to a preferred embodiment of the invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
In FIG. 1, a table device 10 for fixing a workpiece of a machine tool includes a table base 12 and a rotary table 16. The machine tool may be, for example, a machining center that processes a workpiece (not shown) attached to a rotating table 16 and a tool (not shown) attached to a main shaft (not shown) of the machine tool by moving them relative to each other. Can be done.

The table base 12 can be attached to, for example, a bed (not shown) that serves as the base of a machine tool. The table base 12 may be attached to one of the three orthogonal linear feed axes of the X, Y, and Z axes, for example, an X-axis slider (not shown) provided movably in the X-axis direction. .

In this embodiment, the table base 12 is a cup-shaped member having an internal space 12a and opening upward in FIG. In the table base 12, a base member 28 is fixed to the internal space 12a. The base member 28 has a shaft portion 28a. The shaft portion 28a can be formed from a cylindrical member extending along the rotation axis O. In this embodiment, the base member 28 is a separate member from the table base 12, but the base member 28 and the table base 12 may be formed integrally.

The rotary table 16 is attached to the table base 12 around the shaft portion 28a of the base member 28, that is, around the rotation axis O. An annular outer cover 50 can be disposed between the outer periphery of the rotary table 16 and the outer periphery of the open end of the table base 12. The outer cover 50 can be fixed to the open end of the table base 12.

A workpiece (not shown) to be processed is fixed to the upper surface of the rotary table 16. In this embodiment, a pallet 20 is used to detachably fix a workpiece to the upper surface of the rotary table 16. That is, the pallet 20 to which a workpiece (not shown) is fixed is detachably fixed to the upper surface of the rotary table 16. A plurality of positioning cones 18 may be disposed on the upper surface of the rotary table 16 to position and secure the pallet 20 relative to the rotary table 16.

Each of the positioning cones 18 is adapted to engage with and grip an engaging portion (not shown) provided on the lower surface of the pallet 20. In order for the positioning cone 18 to grip the engaging portion of the pallet 20 and release the gripped engaging portion, a fluid pressure is provided in the rotary table 16 and the table base 12 to supply fluid pressure to the positioning cone 18. A circuit can be installed. In this embodiment, the fluid pressure circuit includes a rotary joint 30 disposed on the shaft portion 28a of the base member 28 of the table base 12. Pressure oil or other working fluid may be supplied to the positioning cone 18 through the rotary joint 30 from a fluid pressure source, such as a hydraulic pump (not shown).

The rotary table 16 is rotatably supported by the table base 12 by a bearing 14 about a rotation axis O. The bearing 14 can be configured by a ball bearing, a roller bearing, or the like. The bearing 14 includes two annular bearings or bearing rings (hereinafter simply referred to as bearing rings) and a rolling element consisting of a plurality of rollers or balls disposed between the two bearings, and rotates. It is arranged between the table 16 and the table base 12. More specifically, the bearing 14 is held between the rotary table 16 and the table base 12 via a rotating bearing retainer 42 and a stationary bearing retainer 44.

The rotating side bearing retainer 42 is fixed to the rotary table 16 and one washer of the bearing 14 (rotating side washer), and the fixed side bearing retainer 44 is fixed to the table base 12 and the other washer of the bearing 14 (fixed side washer). fixed to the bearing raceway). In this way, the fixed side bearing retainer 44 is fixed to the table base 12, and the rotating side bearing retainer 42 rotates with respect to the fixed side bearing retainer 44 together with the rotary table 16.

The table device 10 includes a drive motor 25 that rotationally drives the rotary table 16. The drive motor 25 is located within the table base 12. The drive motor 25 may be a servo motor having a rotor 22 attached to the rotary table 16 and a stator 24 attached to the table base 12 so as to face the rotor 22. In this embodiment, the rotor 22 is coupled to the rotating bearing retainer 42 by a suitable coupling method, for example, a plurality of bolts 40 extending in the axial direction, so as to rotate together with the rotating bearing retainer 42 around the rotational axis O. has been done. In this way, the rotor 22 is coupled to the rotating table 16 and the rotating washer of the bearing 14 via the rotating bearing retainer 42.

The table device 10 further includes a fin assembly 26 as a heat exchanger for cooling the rotor 22. Fin assembly 26 has annular outer fins 26a and inner fins 26b. The outer fin 26a includes a cylindrical member and a plurality of fin members formed on the inner peripheral surface of the cylindrical member. The outer fin 26a is formed by bringing the outer circumferential surface of the cylindrical member into close contact with the side surface of the rotor 22 opposite to the stator 24 (the side surface opposite to the side facing the stator 24), and attaching it appropriately such as by brazing. Installed by method. The outer fin 26a is further coupled to the rotating bearing retainer 42 by a suitable coupling method, such as a plurality of axially extending bolts 38, so as to rotate together with the rotating bearing retainer 42 about the rotational axis O. There is.

The inner fin 26b includes a cylindrical member and a plurality of fin members formed on the outer peripheral surface of the cylindrical member. The inner fin 26b is fixed to the table base 12 at the inner circumferential surface of the cylindrical member by a suitable joining method such as brazing. In this embodiment, the inner fin 26b is fixed to the base member 28 of the table base 12.

The fin member of the outer fin 26a is formed into a plate shape, particularly an annular shape, extending in a direction perpendicular to the rotation axis O. The plurality of fin members are arranged at equal intervals in the rotational axis O direction along the inner peripheral surface of the cylindrical member of the outer fin 26a. The fin member of the outer fin 26a can be integrally formed with the cylindrical member. For ease of manufacture or attachment to the base member 28, the outer fins 26a may be halved longitudinally.

The fin members of the inner fins 26b are similarly formed from a plurality of plate-like, particularly annular, fin members extending in a direction perpendicular to the rotation axis O. The plurality of fin members of the inner fin 26b are arranged at equal intervals in the direction of the rotation axis O along the outer peripheral surface of the cylindrical member. The fin member of the inner fin 26b can be integrally formed with the cylindrical member. For ease of manufacture or attachment to the base member 28, the inner fins 26b may be cut in half lengthwise.

The outer fins 26a and the inner fins 26b are arranged such that the respective plurality of fin members do not come into contact with each other, and the fin members of the outer fins 26a and the fin members of the inner fins 26b are arranged alternately in the axial direction. is positioned. When the rotary table 16 rotates, between the fin members of the inner fins 26b fixed to the table base 12, each fin member of the outer fins 26a fixed to the rotor 22 rotates around the rotation axis O together with the rotor 22. Rotate as .

While the drive motor 25 rotates the rotary table 16, the drive motor 25 generates heat. Heat generated from the rotor 22 of the drive motor 25 is transported to the outer fins 26a by thermal conduction. The heat transported to the outer fins 26a is further transported to the inner fins 26b by convective heat transfer via the air between each fin member of the outer fins 26a and the inner fins 26b. At this time, the outer fins 26a rotate together with the rotor 22 relative to the stationary inner fins 26b, so that the air between the outer fins 26a and the inner fins 26b is transferred to the fins of the rotating outer fins 26a. The member rotates around the rotation axis O with respect to the fin member of the inner fin 26b, increasing the convective heat transfer coefficient, and making it possible to efficiently transfer heat from the outer fin 26a to the inner fin 26b.

The heat transported to the inner fins 26b can be dissipated throughout the table base 12 by thermal conduction. Alternatively, in order to enhance the cooling effect, the inner fins 26b may be cooled with a coolant such as a cooling liquid or a cooling gas. As an example, the table apparatus 10 can include a fin coolant passage 32, as shown in FIG. The fin coolant passage 32 can be arranged, for example, in the table base 12, particularly in the base member 28 of the table base 12, so as to face the inner circumferential surface of the inner fin 26b. The fin coolant passage 32 can be defined by a recess formed in the outer peripheral surface of the base member 28 and the inner peripheral surface of the cylindrical portion of the inner fin 26b. The fin coolant passage 32 can preferably be formed over the entire circumference of the outer peripheral surface of the base member 28 .

When the fin cooling liquid passages 32 are provided, the base member 28 can be formed with a cooling liquid supply passage 34a communicating with the fin cooling liquid passages 32 and a cooling liquid discharge passage 34b. Preferably, the coolant supply passage 34a and the coolant discharge passage 34b can be arranged at 180 degrees with respect to the rotation axis O. Preferably, the coolant supply passage 34a opens to the fin coolant passage 32 in the axial direction below the base member 28 in FIG. 1, and the coolant discharge passage 34b opens in the axial direction above the base member 28 in FIG. It can be formed to open into the fin coolant passage 32 at the side.

The coolant supply passage 34a and the coolant discharge passage 34b are connected to a coolant supply source (not shown) via a coolant supply pipe (not shown) and a coolant recovery pipe (not shown), respectively. You can do it like this. The coolant supply source includes, for example, a tank (not shown) that stores the coolant, a cooling device (not shown) that cools the coolant in the tank to a predetermined temperature, and a pump that pumps the coolant in the tank. (not shown). The coolant from the coolant supply source is supplied into the fin cooling passage 32 via the coolant supply pipe and the coolant supply passage 34a, and after cooling the inner fin 26b, the coolant is passed through the coolant discharge passage 34b and the coolant recovery passage 34a. It is recovered via a line to the tank of the coolant supply source.

Heat generated from the stator 24 of the drive motor 25 while rotating the rotary table 16 can be dissipated throughout the table base 12 by heat conduction. Alternatively, in order to enhance the cooling effect, the outer circumferential surface of the stator 24 may be cooled with a coolant such as a cooling liquid or a cooling gas. As an example, the table apparatus 10 can include a stator coolant passage 36, as shown in FIG.

The stator coolant passage 36 can be formed, for example, on the outer circumferential surface of a stator jacket 46 made of a cylindrical member disposed so as to be in close contact with the outer circumferential surface of the stator 24. More specifically, the stator coolant passage 36 is defined by a spiral groove formed on the outer circumferential surface of the stator jacket 46 and a cover 48 made of a cylindrical member that tightly fits onto the outer circumferential surface of the stator jacket 46. can do.

As in the case of the fin coolant passage 32, the stator coolant passage 36 is connected to a coolant supply pipe (not shown) and a coolant supply passage (not shown) formed in the table base 12 from a coolant supply source. coolant is supplied from the stator coolant passage 36 through a coolant discharge passage (not shown) formed in the table base 12 and a coolant recovery pipe (not shown). can be collected.

Since the rotor 22 of the drive motor 25 that rotationally drives the rotary table 16 rotates around the rotation axis O, conventionally it has been difficult to cool it, but according to the present embodiment, it can be effectively cooled by the fin assembly 26. It becomes possible to do so. Since the rotor 22 is thermally coupled to the bearing 14 via the rotation-side bearing retainer 42, by cooling the rotor 22, it is possible to prevent the bearing 14 from overheating. This makes it possible to rotate the rotary table 16 at high speed, and it becomes possible to turn a workpiece (not shown) attached to the rotary table 16 while rotating it around the rotation axis O.

10 Table device 12 Table base 14 Bearing 16 Rotary table 22 Rotor 24 Stator 25 Drive motor 26 Fin assembly 26a Outer fin 26b Inner fin 28 Base member 32 Fin coolant passage 34a Coolant supply passage 34b Coolant discharge passage 36 Stator coolant aisle

Claims (3)

In the table device that fixes the workpiece of the machine tool,
table base and
a rotary table rotatably attached to the table base around a predetermined rotation axis;
a drive motor that rotationally drives the rotary table, the drive motor having a rotor coupled to the rotary table and a stator coupled to the table base so as to face the rotor;
The rotor includes a cylindrical member coupled to a side surface opposite to the side surface facing the stator, and a plurality of fin members formed on an inner circumferential surface of the cylindrical member, the plurality of fin members comprising: outer fins formed in a plate shape arranged in the direction of the rotation axis and extending in a direction perpendicular to the rotation axis;
an inner fin having a plurality of plate-shaped fin members disposed between the fin members of the outer fin and fixed to the table base;
a fin refrigerant passage through which refrigerant for cooling the inner fins flows;
A table device comprising: The table device according to claim 1, further comprising a stator refrigerant passage through which a refrigerant for cooling the stator flows. The table device according to claim 1, further comprising: a bearing that rotatably supports the rotary table on the table base; and a bearing retainer disposed between the bearing and the rotary table and coupled to the rotor. .

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